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Chromium occurs mostly in tri- and hexavalent states in the environment. Hexavalent chromium [Cr(VI)] compounds are extensively used in diverse industries, and trivalent chromium [Cr(III)] salts are used as micronutrients and dietary supplements. In the present work, we report that they both induce genetic mutations in yeast cells. They both also cause DNA damage in both yeast and Jurkat cells and the effect of Cr(III) is greater than that of Cr(VI). We further show that Cr(III) and Cr(VI) cause DNA damage through different mechanisms. Cr(VI) intercalates DNA and Cr(III) interferes base pair stacking. Based on our results, we conclude that Cr(III) can directly cause genotoxicity in vivo. [ABSTRACT FROM AUTHOR]

Background: Two strains of Vibrio parahaemolyticus (ATCC 17802 and 33847) in shrimp, oyster, freshwater fish, pork, chicken and egg fried rice were evaluated for production of hemolysin and exoenzymes of potential importance to the pathogenicity of this bacterium. Results: The two strains of V. parahaemolyticus produced hemolysin, gelatinase, caseinase, phospholipase, urease, DNase and amylase in selected food matrices. Significantly higher (p < 0.05) hemolytic activity was produced by V. parahaemolyticus in egg fried rice > shrimp > freshwater fish > chicken > oyster > pork. But the exoenzyme activities were not consistent with the hemolytic activity profile, being significantly higher (p < 0.05) in shrimp > freshwater fish > chicken > oyster > pork > egg fried rice. Filtrates of V. parahaemolyticus from shrimp, freshwater fish and chicken given intraperitoneally to adult mice induced marked liver and kidney damage and were highly lethal compared with the filtrates of V. parahaemolyticus from oyster > egg fried rice > pork. Conclusion: From in vitro and in vivo tests, it appears that the food matrix type has a significant impact on the activity of extracellular products and the pathogenicity of V. parahaemolyticus. From a food safety aspect, it is important to determine which food matrices can stimulate V. parahaemolyticus to produce additional extracellular factors. This is the first report of non-seafood including freshwater fish and chicken contaminated with V. parahaemolyticus to have been shown to be toxic to mice in vivo. [ABSTRACT FROM AUTHOR]

The heavy metal cadmium is widely used and released into the environment, posing a severe threat to crops and humans. Saccharomyces cerevisiae is one of the most commonly used organisms in the investigation of environmental metal toxicity. We investigated cadmium stress and the adaptive mechanisms of yeast by screening a genome-wide essential gene overexpression library. A candidate gene, OLE1, encodes a delta-9 desaturase and was associated with high anti-cadmium-stress activity. The results demonstrated that the expression of OLE1 was positively correlated with cadmium stress tolerance and induction was independent of Mga2p and Spt23p (important regulatory factors for OLE1). Moreover, in response to cadmium stress, cellular levels of monounsaturated fatty acids were increased. The addition of exogenous unsaturated fatty acids simulated overexpression of OLE1, leading to cadmium resistance. Such regulation of OLE1 in the synthesis of unsaturated fatty acids may serve as a positive feedback mechanism to help cells counter the lipid peroxidation and cytoplasmic membrane damage caused by cadmium., Importance: A S. cerevisiae gene encoding a delta-9 desaturase, OLE1, was associated with high anti-cadmium-stress activity. The data suggest that the regulation of OLE1 in the synthesis of unsaturated fatty acids may serve as a positive feedback mechanism to help yeast cells counter the lipid peroxidation and cytoplasmic membrane damage caused by cadmium. The discovery of OLE1 involvement in membrane stability may indicate a novel defense strategy against cadmium stress., (Copyright © 2016 American Society for Microbiology.)

The asymmetric transfer hydrogenation of a series of diynones has been achieved in high conversion and enantiomeric induction. When R(1) is a phenyl group, a competing alkyne reduction takes place; however, when R(1) is an alkyl group, this side-reaction is not observed. The application of the reduction to the total synthesis of the natural product (S)-panaxjapyne A in high enantiomeric excess is described.

Toona sinensis and Moschus are two herb materials used in traditional Chinese medicine, most commonly for their various biological activities. In this study, we investigated the inhibitory effect of three decoctions from Toona sinensis, Moschus, and Toona sinensis and Moschus in combination on cell growth in several normal and cancer cell lines by cell viability assay. The results showed that the combined decoction exhibited the strongest anticancer effects, compared to two single decoctions. The observations indicated that the combined decoction did not induce cell apoptosis and autophagy in HeLa cells by fluorescence microscopy. Flow cytometry analysis revealed that the combined decoction arrested HeLa cell cycle progression in S-phase. After the decoction incubation, among 41 cell cycle related genes, eight were reduced, while five were increased in mRNA levels by real-time PCR assay. Western blotting showed that there were no apparent changes of protein levels of Cyclin E1, while P27 expression significantly declined and the levels of CDC7 and CDK7 obviously increased. The data suggest that the RB pathway is partially responsible for the decoction-induced S-phase cell cycle arrest in HeLa cells. Therefore, the combined decoction may have therapeutic potential as an anticancer formula for certain cancers.